"Mercy” is the one expletive my grandmother Norris allowed herself, the all-purpose exclamation for times when she was too awestruck, befuddled or exasperated to say anything else. During the '60s, I considered her “Mercy” to be amusing and even charming, but also embarrassingly anachronistic. Now that I am older, however, "Mercy" seems a fine word for moments when other words fail.